Hopper construction



July 28, 1925.

F. B. ALLEN HOPPER CONSTRUCTION File ec, '31. 9

2 Sheets-Sheet 1 INVENTOR ATTO EY July 28, 1925..

F. B. ALLEN HOPPER CONSTRUCTION Filed Deg. 51. 1923 2 Sheets-Sheet 2 Q fin INVENTOR BY 1M Al zoRNEY Patented July 28, 1925.

PATENT OFFICE.

FRANK B. ALLEN, OF CYNWYD, PENNSYLVANIA.

HOPPER cousrnoc'rrou.

Application filed December 31, 1923. Serial No. 683,792.

To all whom it may concern:

Be it known'that-I, FRAN B. ALLEN, a citizen of United States, residing at Cynwyd, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Hopper Constructions, of j which the following is a specification.

My invention relates to hopper construction and especially to a hopper door and associated parts for a hopper for solid material through which a quantity of liquid passes.

One object of the invention is to construct "a hopper wall, door and door frame adapted to control the flow ofliquid through the hopper in anew and improved manner.

Another object is to construct a door and door, frame for a hopper. having a bottom opening adapted to'be liquid sealed bywaterj passing freely through the hopper.

Another object is to construct a hopper.

door an'd door frame which will permit the free escape of water from the-hopper along all sides of the door and which will conduct the-escaping water above or on the top of the door and discharge it at one end thereof. Another object is to construct a new and improved door for a hopper having a bottom opening provided with guide surfaces and roller engaging track surfaces, said surfaces being protected from material passing through the hopper opening and being self cleaning.

A further object is to construct a new and improved hopper door and door frame which cooperate to retain solid material in the hopper and to permit the'escape of liquid from the hopper while maintaining a liquid seal between the hopper and door.

Another object is to construct a new and improved means for mounting and maintaining a movable hopper door in operative position with respect to the door frame/of a hopper having a bottom opening.

Other objects including refinement of old parts, the provision of new and improved parts and general simplicity of construction and operation of parts will appear and be described hereinafter.

In'the drawings accompanying and forming a part of this specification:

Figure 1 is a fragmentary perspective view partly in section of a hopper and associated parts constructed in accordance with my invention. Y

Figure 2 is a sectional view through the, hopper door and frame. taken on line 2-2 of Fig. 1.

- Figure 3 1s a side elevation of the hopper door frame and associated parts shown in Figure 1.. Figure 4 is an enlarged fragmentary view taken on line 4-4 of Fig. 3, and Figures ,5 and 6 are fragmentary cross sectional views showing, diagrammatically, modified forms of door construction.

Although my invention pertainsbroadly to hoppers of various types and for various uses, I have chosen hereinafter to describe the embodiments thereof which I prefer to employ in connection with ash hoppers for steam generating boilers.

Referring to Fig. 1, 1 indicates. the skeleton uprights of a hopper having a bottom opening; 2 I indicates substantially parallel side members carried by uprights 1 and between which a door frame 3 is secured, the members 2v engaging opposite sides of the frame 3 and extending beyond the frame.

The uprighthopper walls are composed of sectional metal plates 4 secured to uprights 1 and having flanges 5 on the inner side to support lining units 6 of refractory material. I It will beunderstood that the hopper here shown is suspended beneath the ash dis charge end of a fire grate or automatic Stoker-in position to receive ashes therefrom.

Door frame 3 which may be a casting-conforms in general outlines to the shape of the bottom of the hopper and the opening in the bottom thereof with which it is to be used. In the modification shown it is, in plan view, rectangular with a substantially rectangular opening through the center. The frame consistsof a top plate 7 from adjacent the outer and-inner edges of which substantially continuous flanges 8 and 9 depend.

Flanges 8 depend from adjacent the outer periphery .of plate 7 and may be thought of as-consisting'of portions'of difierent lengths. The longitudinal side flanges have for convenience been referred to as flange portions 8, while similarly the front and rear end flanges 8 have been called flange portions 8 and 8 respectively. In this manner, small differences between the various portions of the flanges 8 are indicated, it being understood that the portions 8 depend farther below the plate 7 than portions 8 and 8 while portion 8 is shorter than portion 8".

Flanges 9 which depend from adjacent to the inner edges of frame 7 are all of substantially the same length and similar in substantially all respects except that in the modification shown in Fig. 4 the longitudinal side flanges 9 have their outer lower edges beveled as at 10 for a purpose later to be described.

From the outer and inner edges of plate 7, flanges or projections 11 and 12 project upwardly. Flanges 12 are preferably cut away at intervals sufficiently for any liquid which may collect between the flanges to escape. The lower edges of the hopper Walls including wall 4 and lining units 6 rest on plate 7 inside of, flanges 11 and may be secured against displacement by and between flanges 11- and 12. In the construction shown no liquid may escape from the hopper between the hopper wall and door frame because of the substantially continuous outer flanges 11 which would necessitate the water flowing upward thereover to escape and because of the cut away parts of flanges 12 which permit escape of any Water from the top of plate 7 At spaced intervals along the side members 2 I mount roller axles or shafts 13, these axles extending substantially at right angles through the members 2 and the flanges 8 of frame 3. Brackets 14 provided .with bosses 15 furnish the necessary bearing and supporting surfaces for shafts 13, these brackets 14 being conveniently secured as by bolts 16 to the exterior of members 2. In the boss 15 of each bracket 14 I find it desirable to mount a set screw 17 so that the shaft 13 may be held in any desired position therein. It will be observed that the shafts may be rotated or moved longitudinally to various positions and then secured in such position. On the inner end of each axle or shaft'13 I provide a roller carrying bearing surface 18 which is formed eccentrically with respect to at least a part of the remainder of the shaft and particularly that portion thereof which has a bearing in the'boss 15 and members 2 and 8. Each roller 19 is adapted to rotate on this eccentric portion 18 and may be lubricated by the grease passage 20 leading through shaft 13 from a suitable grease receptacle 21 at the outer end thereof. I mount a guide strip 22 in a substantially horizontal position extending past all of the shafts 13 on' one side of the frame and a similar guide strip 22 on the shaft or axles 13 on the other side of the frame, and preferably secure these wear strips directly to the shafts 13 by screws 23 or other suitable securing means entering the shafts concentrically with respect to the portion thereof which bears in the bosses 15. It will be understood that by loosening the set screws 17 I may rotate separately the shafts 13 thereby raising or lowering the rollers 19 without noticeable effect on the vertical position of the guide strip 22 since the latter is mounted concentrically of the outer end of the shaft 13. Likewise longitudinal adjustment of the shafts with coincident horizontal movement of the strips 22 will produce any desired clearance between the guide strips and the sides of door 24 without altering the vertical position of the rollers 19.

24 indicates a door for the bottom opening of the hopper. It may conveniently be formed by a single casting and preferably consists of a body portion 25 of substantially the same area as is defined by the flanges 9 of frame member 3 provided with refractory lining units 26 over substantially this entire area. At thelongitudinal sides and rear end of the door 24 are formed flanges 27 and 28 extending upwardly and outwardly from the top of the door. These flanges may be variously shaped and variously secured to the door 24 but may conveniently be cast integral therewith and with each other as shown.

The purpose of these flanges is in part to prevent escape of ashes from the hopper while permitting water to flow into the spaces or channels between [the flanges 9, and 27 and 28 and be discharged at one end of the door. To carry out this purpose the flanges 27 and 28 may advantageously extend upwardly and outwardly from the top of the door 24 but certain other forms may be used provided the major portions thereof effective for carrying water as described are located above the top of the door.

The side flanges 27 are provided with substantially horizontal roller engaging track surfaces 29 on the underside near the outer ends of flanges 27. The door is also providedwith a bracket 32 on its underside to which may be secured a rod 33 and connected means for actuating the door which are not shown.

It will be understood that when door 24 is assembled with the hopper and door frame 3 asshown in Fig. 1 it can be moved along below the frame into and out-of sition beneath the hopper opening, the side flanges 27 of the door providing the means for supporting the door on the rollers 13. It will further be noted that due to the location of rollers .19 at some distance from the opening in the frame 3 through which the ashes are discharged and the flanges 9 projecting below the tops of the rollers there will be little tendency for any ashes to collect on the rollers. This tendency is further decreased by the inclination and locationof the side flanges27 since ashes lying thereon will tend to move down onto the flat top of the door when the flanges 9 have swept the ashes off the door top as the door opens. Any lashes alighting on rollers will fallfoif as soon as the roller turns. The tracks, being inverted, breakage of parts of the door .or frame structure due to careless workmen leaving tools on the trackswill be avoided.

Lateral movement of the door with respect to the frame 3 is regulated by horizontal adjustment of .guide strips '22 through proper positioning of shafts 13 toward or away from surfaces 30 of door 24. Bymeans of the shafts 13 and the eccentric mounting of rollers '19 thereon the door 24 may be raised or lowered so as to regulate as desired the space between the depending flanges 9 of frame 3 and the top of door 24 or the flanges 27 and 28. The longitudinal side flanges 9 are beveled as at 10 to correspond with the inclination of the top and adjacent surface of flanges 27 Preferably a small space is left between the adjacent surfaces of'flanges 9. and door 24 so that Water or other liquid passing through the hopper may escape therebetween. Such escaping liquid will feed into the bottom of and tend to fill the trough-like spaces or channels between thev depending flanges 9 of frame I 3 and the upwardlyinclined flanges 27 and 28 of door 24, and will discharge from the open ends of these spaces or channels at the front. end of the door. Likewise liquid passing over the horizontal flange 31 will be discharged at the front end of door. The presence of a head of water between flanges 9 and 27 and28 on three sides of the door 24 acts as aliquid seal between the door and door frame and furthermore acts as a pressure head which forces a major portion of the water from the. hopper over the front end of the door and across flange 31. Because the space hetween the flange 9 andthe door top is small at this point, the water if in sufliclent amount will back up and form a liquid seal all along this fourth side of the door thereby making the door liquid sealed around its entire periphery. Very few ashes, however, .will escape through the small spaces.

between flanges 9 and door, 24 but such as do creep through will fall back onto the central portion of the door when the latter is moved out of position beneath these flanges, as when ashes are being discharged from the hopper. I

To collect and conduct away the liquid passing through the hopper I have provided at the front end of the door .24 a stationary 'outer ends-thereof may be provided with any suitable wrench attaching means as will "be understood by those skilled in the art.

In'some instances-it may be desirable to provide holes 36 through plate 7 over'the stationary trough 34 to permit escape of liquid from the top of plate 7 into trough 34. Liquid flowing through these holes may flow down the depending flange 81o cated over trough 34 and near the flange portion 8 of end of door 24 which is not equipped with the upwardly and outwardly extending flange 28, namely the end along which flange 31 is located. It will be observed (see Fig. 2) that" the portion 8 of these flanges 8 8 extends to a point below the top of door 24 or flange 31 so that liquid flowing on the door toward the said portion 8" will be deflected down into trough 34.

In Fig. 51 have shown a door 38, similar to door 24 but provided with side portions 39 extending 'outwardly'and upwardly from a point adjacent to or somewhat below the top of the door proper to a point well above the top thereof and above the bottom of A the inner flange 9 of door frame 3. This construction in actual operation is substantially like the form shown in Figs. 1 to 4, since ash will tend to fill the small channel between the top surface thereof and the side of the door.

In Fig. 6 I have shown a door 40,.similar to door 24 but having upright side portions 41 arising from the top of the door outside of and spaced apart fromflanges 9 of frame 3 from the upper edge of which portion a lateral projection 42 extends outwardly and furnishes a door supporting member to rest on rollers .19. Lateral projections 43 serve as guideslto engage guide strips 22.

It is to be understood that I do' not consider it essential that the portions or flanges- 27, 39 or 41 must necessarily furnish also bearing surfaces for. engagement with the door supporting means although it is highly advantageous and desirable.

It will be understood that each flange 27 and '28, 39 and 41, extends well above the top of the body ortion 25 of the door; that is to a point su ciently high thereabove so that practically all water passing through the hopper will be discharged from one end of the door before it can back up between flanges 9, 27 and 28 and overflow flanges 27 or 28..

It will furthermore be observed that I have provided means at opposite sides of the door, here illustrated as side flanges 27, 39 or 41, which cooperate with end flange 28 and serve to direct substantially all the water falling on the door to one end thereof.

It will be noted that the door 24 not only cooperates with the frame to form a solid material retaining closure for the hopper discharge opening, but also cooperates with the inner depending flanges 9' to form bottom fed liquid carrying channels of relatively large liquid carrying capacity, say several gallonsper minute. The depending stationary flanges 9 constitute the inner side walls of these channels, while the flanges 27 and 28, 39 and 41, which are mounted to move with the door, constitute the bottom and/or outer side walls of the channels. Inclined flanges such as 27 and 28 form both bottom and outer side walls of the channels.

Having thus described my invention, what I desire to secure by Letters Patent is defined in what is claimed' What is claimed is:

1. A. horizontally movable door for a hopper having a bottom opening, said door comprising a body portion and having flanges extending upwardly and outwardly from the top of said body portion along thrce sides thereof for directing water dropping upon said door, toward the fourth side, the

fourth side of the door being formed to dis-.

charge such water at a level substantially that of the top of, and well beyond the body portion of the door.

2. A door, for a hopper having a bottom opening, provided with flanges on the opposite longitudinal sides thereof extending upwardly and outwardly from the top of the body portion of the door, and guide surfaces along the longitudinal sides of the door disposed inwardlyof the outer edges of the said flanges.

3. A door, for a hopper having a bottom opening provided with flanges on opposite longitudinal sides thereof extending upwardly and outwardly-from the top of the body portion of the door, the said flanges being provided with supporting surfaces on the underside nearthe outer edges thereof.

4. A door, for a hopper havinga bottom opening, provided with flanges on opposite sides thereof extending upwardly and out,- wardly from the to of the body portion of the door, said anges being provided with supporting surfaces on the underside near the outer edges thereof and also with guide surfaces located inwardly of the said supporting surfaces.

5. A door, for a hopper having a bottom opening, provided with outwardly extending longitudinal flanges having substantially horizontal, surfaces on their undersides adjacent their outer edges, and substantially vertical guide surfaces along the underside of the said flanges and inwardly of the first said surfaces.

6. In combination with a hopper having a bottom opening, a door frame having a central opening and'depending flanges adjacent to the said opening, a horizontally movable door cooperating with -the said frame and comprising inclined flanges on three sides of the door extending outwardly and upwardly from the top of the body portion of the door to points above the lower edges of the said flanges on the frame to form with the said depending flanges liquid carryingchannels discharging at substantially the level of the bottom edges of the depending flanges.

7. In combination with a hopper having a bottom discharge opening, a door frame surrounding the opening, side members disposed on opposite sides of the frame and operatively connected to the frame and hopper, roller shafts carried by the said side members and extending inwardly therefrom, rollers mounted on the inner ends of the said shafts, and a door mounted to run on the said rollers and cooperating with the said frame to form a movable closure for the said discharge opening.

8. In combination with a hopper having a bottom discharge opening, a door frame surrounding the opening, side members disposed on opposite sides of the said frame and operatively connected to the hopper and frame, roller shafts carried by the side members and extendin inwardly therefrom, rollers mounted on t e inner ends of the said shafts for vertical adjustment independently of each other, and a door mounted to run on the rollers and cooperating with the said frame to form a movable closure for the said discharge opening.

9. In combination with a hopper having a bottom discharge opening, a door frame surrounding the opening and operatively connected to the said hopper, substantially parallel members engaging opposite portions of the frame and extending beyond one end thereof, roller shafts carried by the parallel members and extending inwardly therefrom rollers on the inner ends of the shafts, and a door mounted to run on the said rollers and cooperating with the said frame to form a movable closure for the said discharge opening.

1O. In combination with a hopper having a bottom opening, a door frame, side each set of axles and a door adapted to rotatably and horizontally adjustable" in the.

members on opposite sides thereof, a setof roller axlesfor each side member'extending through and being rotatably and horizontally adjustable in the said side member's, rollersmounted on the inner ends 'of' the said'axles, guide strips secured to the inner ends of operate with the said frame andguide strips and to run on the said rollers.

' 11. In combinationwith' a hopper having a bottom opening,-a door frame, sets of oppositely disposed roller axles extend ng through and beingrotatably' and horizontally adjustable in the said frame, rollers. mounted on the inner ends of the said axles, guide strips secured to the, inner ends of each setv of axles and aT'do'dr adapted to cooperate withthe 'said frame and guide strips and to run on the said rollers.

. 12. In combination with'a hopper-havinga bottom opening,- a door frame having d'e-I pending outer and inner flanges along its outer and inner periphery, roller--axles passing through the outer flanges, rollers mounted on the axles between the outer and inner flanges on opposite sides of 'the frame, and

'a door cooperating with the said frame and having portions extending-upwardly and outwardly into the space tween the said flanges and adapted to run on the top of the said rollers.

y 13. In combination with a. hopper having abottom' opening, a. door frame, side' 'members'on opposite sides thereof, a plurality of roller axles extending through and being said side members, rollers mounted on the inner ends of the said axles, guide strips oppositely disposed with 'respectto the said door and secured to the'inner 'ends'of the axles, and a door adapted-to cooperate with the frame and guide strips and to run on the said rollers.

1 4. In combination with a liopperhaving a bottom opening, a door frame having outer flanges depending from the outer periphery thereof, a plurality of roller axlesextending through and being rotatably and horizontally adjustable in the oppositely disposed outer flanges, rollers mounted on the inner ends of the said axles, guide stri s oppositely disposed with respect to the sand door and secured to the inner ends of the axles, and a door adapted to cooperate with v the frame and guide strips and to run on the said rollers.

{15. In combination. with a hopper having a bottom opening, a door frame for the opening, substantially parallel members engagin opposite ortions of the frame and exten ing beyon the frame, roller shafts in thesaid frame and in the parallel mem "bers, rollers on the shafts, guide strips on the shafts, and a'door adapted to cooperate said rollers, the said rollers being adjustable in a vertical plane and the said guide strips being adjustable in a horizontal plane.

In combination with a hopper having a bottom opening, a door frame, side members on opposite sides thereof, a plurality of roller shafts extending through the said side members, rollers mounted on the inner ends of the said shafts,oppositely-disposed guide strips secured to the inner ends of the said shafts and a door cooperating with the said frame and guidestrips and being supported on the said rollers, the said rollers in being ad'ustab'le .ina vertical plane and the said ui e strips being adjustable in a-horizonta plane, the rollers and guide strips being each capable of the said respective adjustments independently of and without disturbing the adjustment of the other; 1

18; In combination with .a hopperv having shafts adjustably mounted in the said side members, each shaft having a bearing surface a-djacent' the inner end thereof, eccentrio with respect to the remaining surface thereof, rollers. mounted. vonthe said eccentric surfaces, oppositely disposed longitudinally extending guide strips secured to a. plurality of shafts, and a" door cooperating with the said door frame and adapted to run on the rollers and be guided horizontally by the guide strips. v

19. In combination with ahopper having a bottom openin'g,-a door frame separately adjustable shafts in the said shaft having a bearing surface adjacent the inner end and eccentricwith respect to the remaining surface thereof, rollers mounted on the" sa d eccentric surfaces,'lon itudlnally extending guide strips secure to a plurality of shafts, and a door cooperating with the said door frame and adapted to run on the rollers and be guided bythe guide strips. 1

' 20.- In' combination with a hopper having a bottom opening, a door frame,.side members on opposite sides thereof, a plurality of separate shafts extending throughthe said side members and ad'ustable therein, each said shaft having a cent its inner end and eccentric withrespect rame, each" earin'g surface adjaa bottom opening, a door frame, side members on opposite sides. thereof, separate to the remaining surface thereof, a roller on each of the said eccentric surfaces, guide strips for a plurality of said shafts, means concentric with the longitudinal axis of the said shafts for securing the guide strips to the inner ends of the shafts, and a door adapted to run on the tops of said rollers and to engage the guide strips on opposite sides of said door.

21. In combination with a hopper having a bottom opening, a door frame comprising a plate having inner and outer sets of de pending flanges, a door cooperating with the said frame and having on the longitudinal sides thereof flanges extending upwardly and outwardly from the top of the body portion of the said door and into the space between the said inner and outer flanges of the frame, shafts projecting through certain of the said outer flanges of the frame member and carrying rollers engaging the underside of said longitudinal flanges and adapted to support the said door.

22. In combination with a hopper having a bottom openingfa frame having inner and outer depending flanges, rollers mounted between the said flanges, a door having inclined flanges extending upwardly into the space between the said depending flanges of the frame, the under surface of the flanges engaging the top of and being movable upon the said rollers.

23. In hopper construction, in combination with a hopper having a bottom opening, a frame having a central opening and depending flanges surrounding and adjacent to the said opening, a door movably mounted beneath the said frame, the said door having a horizontally extending flange at the front end,.an upwardly inclined flange at its rear end, and outwardly and upwardly inclined flanges at the sides joining the said rear flange and extending to the front end of the said horizontal flange, the said inclined flanges extending from the top of the body portion of the door to points well thereabove.

24. In hopper construction, in combination with a hopper having a bottom opening, a frame having a central openingand depending flanges surrounding and adjacent to the said opening, a door movably mounted beneath the said frame, the said door having a horizontally extending flange at the front end, an inclined flange at its rear end, and outwardly inclined side flanges joining the said rear flange and extending to the front end of the said horizontal flange, and a stationary trough mounted beneath the front ends of the horizontal and side flanges of the door, the said inclined flanges extending from the top of the body portion of the door to points thereabove.

25. In combination with a hopper having a rectangular bottom discharge opening, a frame operatively connected to the hopper and surrounding the discharge opening, the frame having depending inner peripheral flanges, and a horizontally movable door cooperating with the frame to form a closure for the said discharge opening, the door comprising a body portion, a liquid intercepting flange extending upwardly and out wardly from the top and along'one end of the body portion, means along the sides of the door for receiving liquid from the said flange and for conducting liquid to the remaining end of the door, and means at the remaining end of the door for discharging liquid well beyond the body portion of the door and at a level below the depending flanges.

26. In combination with a hopper having a rectangular bottom discharge opening, a frame operatively connected to the hopper and surrounding the discharge opening, a frame having depending inner peripheral flanges, and a horizontally movable door cooperating with the frame to form a closure for the said discharge opening, the door comprising a body portion, liquid intercepting flanges extending upwardly and outwardly from the top of the body portion and along one end and both sides thereof, and means at the remaining end of the door for discharging liquid well beyond the body portion of the door and at a level below the depending flanges.

27. In combination with a hopper having a bottom opening, a frame having a central opening surrounding the said opening and having upstanding flanges along the outer edges thereof, and depending flanges along the inner edges thereof, hopper walls extending below the top edge of and within the said upstanding flanges, and a door cooperating with the said frame and having a plurality of edge portions extending upwardly from the top of the body portion of the door above the bottom and outside of the said de pending flanges.

28. In combination with a hopper having a bottom opening, a frame having upstanding flanges along the outer edges thereof and depending flanges along the inner edges thereof, hopper walls extending below the top edge of and within the said upstanding flanges, a substantially rectangular door co-- opening and surrounding the said opening and having upstanding flanges and depending flanges along the outer and inner edges thereof respectively,-hopper walls extending below and within the top edge of the said upstanding flanges, and a door cooperating with the said frame and having portions extending above the bottom of the said depending flanges.

30. In combination with a hopper having a bottom opening, a door frame, a plurality of roller shaftsonopposite sides of the said frame, rollers on the inner ends of the shafts, guide strips secured to the said shafts, and a door cooperating with the said frame running on the rollers and being guided by the guide strips, the said rollers being adjustable in a vertical plane andthe guide strips being adjustable in a horizontal plane, the said rollers and guide strips being each ca able of the said respective adjustments 1ndependently of and without effecting the adjustment of the other.

31. A gate construction for an ash hopper having a bottom opening, comprising a stationary member surrounding said opening and having downwardly extended flanges adjacent the opening along the sides and an end thereof, a door mounted for horizontal movement into open and closed position in respect to said opening, said door being adapted to cooperate with said stationary member when in closed position to substantially prevent the escape of ashes between the door and stationary member, said door having outer. upstanding flanges projectingv above the bottom of and spaced apart from the said depending flanges to form bottom fed liquid carrying channels of relatively large liquid carrying capacity whereby liquid collecting on said door will be disa discharge opening in its lower portion, a

frame operatively connected to the hopper and surrounding the said opening, the frame having a depending flange, a horizontally movable door constituting a movable closure for the said opening, the said door having an upstanding flange along one end cooper ating with the said depending flange to form Walls of a bottom fed liquid carrying channel, the said upstanding and depending flanges being relatively movable horizontally, and means for discharging liquid at a level below said depending flange.

33. In combination with a hopper having a discharge opening in its lower portion, a frame operatively connected to the hopper and surrounding the said opening, a frame having depending flanges along a plurality of edges thereof, a door constituting a movable closure for the said opening and having upstanding flanges along a plurality of the edges thereof, the upstanding and depending flanges cooperating to form walls of bottom fed liquid carrying channels, one wall of each of said channels being movable with respect to other walls thereof, and means for discharging liquid at a level below said depending flanges.

In testimony whereof I hereunto aflix my signature this 12th day of December, 1923.

FRANK B. ALLEN. 

